Final answer:
The answer is c. creditor substitution of the original debtor with a new one.
Step-by-step explanation:
The answer to the question is c. creditor substitution of the original debtor with a new one. This is not a suretyship defense because when the creditor substitutes the original debtor with a new one, the surety is still bound by the obligation.
On the other hand, the other options can serve as suretyship defenses. For example, the statute of limitations sets a time limit within which a creditor can sue a surety for the debt. If this time limit passes, the surety may be released from liability.
Performance of the obligation by the principal debtor also acts as a defense because if the principal debtor pays off the debt, the surety is no longer responsible for it.
Insolvency or bankruptcy of the principal debtor can also release the surety from further liability as the debtor may no longer be able to fulfill their financial obligations.
Learn more about Suretyship defenses